It is well known to catalyze the alkylation of aromatics with a variety of Lewis or Bronsted acid catalysts. Typical commercial catalysts include phosphoric acid/kieselguhr, aluminum halides, boron trifluoride, antimony chloride, stannic chloride, zinc chloride, onium poly(hydrogen fluoride), hydrogen fluoride, solid acid catalysts such as acidic sulfonic acid ion exchange resins, for example Amberlysts®, solid acid clays and acidic zeolitic materials. Alkylation with lower molecular weight olefins, such as propylene, can be carried out in the liquid or vapor phase. For alkylations with higher olefins, such as C16+ olefins, the alkylations are done in the liquid phase.
There is increasing evidence that certain synthetic and natural chemicals may act as agonists or antagonists to estrogens or androgens and may interfere in multiple ways with the action of thyroid hormones; such compounds can be called endocrine disruptors. For example, endocrine disruptors can mimic or block chemicals naturally found in the body, thereby altering the body's ability to produce hormones, interfering with the ways hormones travel through the body, and altering the concentration hormones reaching hormone receptors. Endocrine disruptors and natural estrogens share a common mechanism of action. In normal cases, estrogenic activity is produced by binding natural estrogen to an estrogen receptor (ER) within the nucleus of the cell, followed by transcriptional activation of these occupied ERs. When endocrine disruptors are present, normal estrogenic activity is supplanted when endocrine disruptors bind an ER, causing transcriptional activation of the ER even though no natural estrogen is present. Similarly, antiestrogenic activity is produced by endocrine disruptors which bind to ERs but which do not subsequently activate the occupied ER as well as natural estrogen. Finally, selective estrogen receptor modulators (SERMs) bind to ERs, but subsequently activate cellular responses that differ from those activated by the natural estrogens. In general, all but a very small number of molecules that bind to ERs produce some activation of the receptors, as either estrogens or as SERMs.
Examples of suspected endocrine disruptors may include, for example: Dioxin, Polychlorinated biphenyls (PCBs), Polybromated biphenyls (PBBs), Hexachlorobenzene (HCB), Pentachlorophenol (PCP), 2,4,5-Trichlorophenoxy acetic acid (2,4,5-T), 2,4-Dichlorophenoxyacetic acid (2,4-D), alkylphenols such as Nonylphenol or Octylphenol, Bisphenol A, Di-2-ethylhexyl phthalate (DEHP), butylbenzyl phthalate (BBP), Di-n-butyl phthalate (DBP), Dicylclohexyl phthalate (DCHP), Diethyl phthalate (DEP), Benzo (a) pyrene, 2,4-Dichlorophenol (2,4-DPC), Di(2-ethylhexyl)adipate, Benzophenone, P-Nitrotoluene, 4-Nitrotoluene, Octachlorostyrene, Di-n-pentyl phthalate (DPP), Dihexyl phthalate (DHP), Dipropyl phthalate (DprP), Styrene dimers and trimers, N-Butyl benzene, Estradiol, Diethylhexyl adipate (DEHA), trans-chlorodane, cis-chlorodane, p-(1,1,3,3-Tetramethylbutyl)phenol (TMBP), and (2,4,-Dichlorophenoxy) acetic acid (2,4-PA).
Alkylphenols and products produced by them have come under increased scrutiny due to their association as potential endocrine disruptive components, which is namely due to the weak estrogenic activity of base alkylphenol as well as degradation intermediates of the alkylphenols products. Alkylphenols commercially are used in herbicides, gasoline additives, dyestuffs, polymer additives, surfactants, lubricating oil additives and antioxidants. In the recent years, alkylphenol alkoxylates, such as ethoxylated nonylphenol, have been criticized for having poor biodegradability, high aquatic toxicity of the by-products of the biodegradation of the phenol portion, and there is an increasing concern that these chemicals may act as endocrine disruptors. Some studies have shown that there are links between alkylphenols and declining sperm count in human males and there is evidence that alkylphenols may harmfully disrupt the activity of human estrogen and androgen receptors.
Concern over the environmental and health impact of alkoxylated alkylphenols has led to governmental restriction on the use of these surfactants in Europe, as well as voluntary industrial restrictions in the United States. Many industries have attempted to replace these preferred alkoxylated alkylphenol surfactants with alkoxylated linear and branched alkyl primary and secondary alcohols, but have encountered problems with odor, performance, formulating, and increased costs. The odor and some of the performance difficulties of the alkoxylated alkyl alcohols are related to the residual free alcohol, which is the portion of the reactant alcohol that does not react with alkylene oxide during the alkoxylation step.